How to find when an object reached the ground using the Quadratic Formula.

Question

You throw a basketball from a height of 3 feet with an upward velocity of 11 feet per second the function h(t) = -16t^2 +11t +3 gives the height h of the basketball after t seconds. When does the ball hit the floor? Round your answer to the nearest tenth.

Answer 1

First of all, the equation given in the question is not correct. The correct equation is

h(t) = -16t² + 11t + 3,

assuming you meant to say the upward velocity is 11 feet per second, not lol feet per second. The ball hits the floor when h=0, so set h(t)=0, and solve the resulting quadratic equation for t using the quadratic formula. You will get a positive and a negative solution. Since time starts at t=0, the positive solution is the correct one.